docs: update minikube tutorial with bootstrapper localkube
docs: update minikube tutorial with bootstrapper localkube

Since minikube can have multiple bootstrappers, we need to specify the
ideal bootstrapper for cilium. For now, only localkube will provide
the minimal etcd version required for cilium.

Signed-off-by: André Martins <bc9800b9d52a24cce72a73dd528afed53f10e5fc@cilium.io>

cilium/cilium,michi-covalent/cilium,michi-covalent/cilium,eloycoto/cilium,cilium/cilium,tgraf/cilium,scanf/cilium,michi-covalent/cilium,tgraf/cilium,scanf/cilium,scanf/cilium,eloycoto/cilium,tklauser/cilium,eloycoto/cilium,tgraf/cilium,scanf/cilium,cilium-team/cilium,eloycoto/cilium,michi-covalent/cilium,eloycoto/cilium,tklauser/cilium,tgraf/cilium,tklauser/cilium,tklauser/cilium,cilium/cilium,cilium-team/cilium,michi-covalent/cilium,cilium/cilium,tklauser/cilium,scanf/cilium,scanf/cilium,eloycoto/cilium,tgraf/cilium,scanf/cilium,cilium/cilium,tgraf/cilium,eloycoto/cilium